Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.
A wireless communication network may include a number of base stations that can support communication for a number of mobile devices. In some technologies, mobile devices may be called access terminals, user equipments (UEs), mobile stations, and the like. A mobile device may communicate with a base station via downlink (DL) and uplink (UL) transmissions. The downlink (or forward link) refers to the communication link from the base station to the mobile device, and the uplink (or reverse link) refers to the communication link from the mobile device to the base station. Each base station has a coverage range, which may be referred to as the coverage area of the cell.
In cellular deployments, a macrocell is used to describe a cell serving a wide region such as rural, suburban, and urban areas. Smaller cells may be deployed in homes, small businesses, buildings, or other limited regions. These small cells may be called “picocells” or “femtocells.” Picocells and femtocells are often connected to a service provider's network via a broadband connection. In 3GPP terms, these cells may be referred to as Home NodeBs (HNB) for UMTS (WCDMA, or High Speed Packet Access (HSPA)) and Home eNodeBs (HeNB) for LTE/LTE-A networks. Some small cells provide access by UEs having an association with the cell, and in some deployments one or more clusters of small cells may provide access by UEs within specific particular areas or buildings (e.g., parks, shopping malls, etc.). Some small cells may be restricted access cells, sometimes referred to as closed subscriber group (CSG) cells. Cells (e.g., macrocells, picocells, femtocells, etc.) that provide access to UEs associated with one or more provider networks without a specific association between the UE and the cell may be called open access cells.
While small cells typically transmit at lower power than macrocells, signals from a small cell may be received at a UE with relatively high signal strength compared to signals received from the macrocell. For example, where a UE is located near a cell edge for a macrocell but relatively close to a remote radio head (RRH) of a small cell, the small cell signals received at the UE may be as strong as or even stronger than the signals received from the macrocell. In instances where the UE is communicating with the macrocell and not the small cell, the UE may have difficulty finding and decoding the appropriate signals from the macrocell for establishing a communication link with the macrocell due to interference from the small cell signals. Similarly, signals from a macrocell may be received at a UE with relatively high strength relative to signals from a small cell. In some such instances, it may be desirable for the UE to establish communications with the small cell and the UE may have difficulty finding and decoding the appropriate signals from the small cell for establishing a communication link with the small cell due to interference from the macrocell signals. Various techniques for interference cancellation/suppression (IC/IS) may be used to reduce or cancel such interference.